REPRODUCTIVE SYSTEM

IMPLANTATION: Attachment of blastocyst to endometrium, digestion of portion of the endometrium, sinking of blastocyst into depression in endometrium, and the thickening of the endometrium around the blastocyst. Implantation begins normally about the end of the first week of development; completed during the second week of development. Following implantation, cells of the trophoblast secrete hCG.

CLEAVAGE: Events of rapid cell divisions and distribution of the zygote's cytoplasm into progressively smaller cells. Blastomeres are cells produced by cleavage. Morula: Solid ball of about 16 cells that remain free in the uterine cavity for about 3 days. Blastocyst: Hollow mass of cells that implants into the endometrium. The two regions of cells of a blastocyst are an inner cell mass and a trophoblast. The inner cell mass gives rise to the embryo proper. The trophoblast gives rise to structures that assist the embryo.

LABIA MAJORA: Lateral rounded folds of fat tissue overlying pigmented skin and hair that extend inferiorly and posteriorly from the mons pubis; covered with hair on the lateral superior surfaces. Enclose and protect other external reproductive organs. LABIA MINORA: Medial folds of skin that are devoid of hair. Form margins of vestibule; protect openings of vagina and urethra. VESTIBULE: Cleft between the labia that contains the hymen, vaginal orifice, urethral orifice, and openings of the paired greater and lesser vestibular glands.

CLITORIS: Small cylindrical mass of erectile tissue, blood vessels and nerves located just posterior to the anterior junction of the labia minora. Produces feelings of pleasure during sexual stimulation due to abundant sensory nerve endings in glans. PREPUCE: Loose fitting casing of skin covering the body of the clitoris. VAGINAL ORIFICE: Occupies a large portion of the vestibule and is bordered by the hymen. URETHRAL ORIFICE: Located in the anterior to the vaginal orifice and posterior to the orifice.

PENIS: Conducts semen and urine to the exterior. 1) Body (Shaft) - consists of the following three columns of erectile tissue, each surrounded by TUNICA ALBUGINEA: 2) Bulb of Penis - Proximal enlargement of the corpus spongiosum.

CORPUS SPONGIOSUM: A single VENTRALLY located column of erectile tissue that contains the penile urethra; column is enlarged at the distal end to form the sensitive, cone shaped area (glans penis). CORPORA CAVERNOSA: TWO DORSALLY located columns of erectile tissue, each one termed a "CORPUS CAVERNOSUM".

CERVIX: Inferior (lower) 1/3 or neck of uterus. Tubular portion extends downward into the superior (upper) part of the vagina. Cervix surrounds CERVICAL ORIFICE (opening), through which uterus opens to the vagina. Undergoes dilation and effacement during labor.

VAGINA: Fibromuscular tube (9 cm) that extends from the uterus to the outside. Located posterior to the urinary bladder and urethra; anterior to rectum.Attached to above structures by connective tissues. Carries uterine secretions to the exterior; receives the penis during sexual intercourse; birth canal.

FOLLICLE MATURATION: Begins at puberty due to FSH secretion by the anterior pituitary gland. Ovaries enlarge in response to increased FSH amounts. Inside each maturing primordial follicle, oocytes enlarge causing surrounding follicular cells to divide MITOTICALLY; giving rise to granulosa cells.

(1) CORONA RADIATA - group of follicular cells that adhere to the oocyte's surface outside the zona pellucidum; and extending through it that supply the oocyte with nutrients. (2) ZONA PELLUCIDA: Thick covering located around the oocyte's membrane, that must be digested by hyaluronidase in order for sperm penetration to occur. Layer of glycoprotein that separates the primary oocyte from the granulosa (follicular) cells...structure is now called primary follicle. (3) THECA EXTERNA: Outer layer of follicle; superficial to the THECA INTERNA and is composed of fibrous connective tissue. (4) THECA INTERNA: Vascular layer of loose connective tissue; immediately adjacent to the region where follicle is maturing. (5) ANTRUM (Follicular cavity): Contains follicular fluid (ESTROGEN)

*MECHANICS F. ERECTION, LUBRICATION & ORGASM* (1) Sexual Stimulation --- (2) Parasympathetic nerve impulses from the sacral portion of the spinal cord --- (simultaneous occurrence) (a) Arteries in the erectile tissue dilate; vagina expands and elongates --- (b) Engorged and swollen vagina increases friction from movement of penis --- (3) Sexual stimulation intensifies --- (4) Vestibular glands secrete mucus to lubricate --- (5) Orgasm: rhythmic contraction of muscles of the perineum; muscular walls of uterus and uterine tubes contract; help TRANSPORT sperm cells through female repro. tract---upper ends of uteri.ne tubes

****FEMALE SEX HORMONES**** Hypothalamus secretes GnRH --- GnRH stimulates anterior pituitary gland to release gonadotropins FSH & LH --- These hormones play a primary role in controlling female sex cell maturation and in producing female sex hormones. Androgens (male hormone): Promote growth of pubic and axillary hair.

GERMINAL EPITHELIUM: Outermost layer of the ovary; produces eggs up to menopause in a process called OOGENESIS -- Process of egg cell formation.

****OOGENESIS PROCESS**** Oogonium --- Mitosis (in fetus) --- Primary Oocyte --- Meiosis I --- 1st Polar Body (small) + Secondary Oocyte (large-future egg cell/ovum) --- Sperm cell Penetration ---Meiosis II --- 2nd Polar Body (tiny) and Ovum ---Zygote (fusion of egg and sperm nuclei)

ESTROGEN (Follicular fluid): Primary source comes from ovaries; some synthesized in adipose tissue from adrenal androgens. Stimulate the enlargement of accessory organs; internal and external structures. Stimulates the endometrium to thicken and is responsible for the development and maintenance of female secondary sex characteristics.

****SECONDARY FEMALE SEXUAL CHARACTERISTICS**** 1. Development of breasts and ductile system of mammary glands in breasts. 2. Increased deposition of adipose tissue in the subcutaneous layer generally and in the breasts, thighs, and buttocks particularly. 3. Increases vascularization of the skin. 4. High levels of estrogens and progesterone inhibit the release of LH and FSH from anterior pituitary.

PLACENTA: Vascular structure formed by the cells surrounding the embryo and cells of the endometrium. Functions to attach the embryo to the uterine wall and to exchange nutrients, gases, and wastes between the maternal blood and the embryo's blood; secretes ABUNDANT placental estrogen and placental progesterone and placental lactogen.

***BIRTH & FEMALE HORMONES*** (1) Placental Estrogens and Progesterone: Maintains the uterine wall, helps the mammary glands make milk, inhibits secretion of LH and FSH, and enlarges the vagina and external reproductive organs. hCG: Secreted by trophoblast. Normally helps to prevent spontaneous abortion; maintains the corpus luteum so it will continue to secrete estrogen and progesterone; inhibits the release of LH and FSH by the anterior pituitary.

MENOPAUSE: Caused by aging of the ovaries. Changes that result from a decrease of estrogens and progesterone are changing of female secondary sex characteristics, shrinkage of breasts, vagina, uterus, and uterine tubes, loss of pubic and axillary hair, thinning linings of urinary and reproductive organs, thinning of skin, and loss of bone mass.

***BIRTH & FEMALE HORMONES*** (2) Placental lactogen: Stimulates breast development; prepares mammary glands to secrete milk with aid of placental estrogens and progesterone Relaxin: Target organ- uterus. Relaxes smooth muscle fibers in the uterus to inhibit uterine contractions. It also relaxes the ligaments joining the symphysis and sacroiliac joints together; allows for movement of joints ...passage of fetus---birth canal. Produced by OVARIES

****SPERMATOGENESIS STAGES**** Spermatogenic Cells (Spermatogonia) ---- Mitosis ---- Primary Spermatocytes (parent cells) ----Meiosis I ---- Secondary Spermatocytes (daughter cells) ---- Meiosis II -- -- Spermatids ---- Mature Sperm Cells (Spermatozoa)

***SECONDARY MALE SEXUAL CHARACTERISTICS*** (1) Increased growth of body hair (facial, chest, axillary & pubic regions) (2) Enlargement of larynx; thickening of vocal folds; lowers pitch of voice. (3) Thickening of skin; strengthening of bones (4) Increased muscular growth, broadening shoulders; narrowing waist.

***STRUCTURAL FEATURES OF THE TESTES*** Connective Tissues (1) Tunica Albuginea- Capsule that surrounds and protects each testis. (2) Mediastinal Testis- thickened extension of the tunica albuginea on the POSTERIOR BORDER of each testis. (3) Septa- extensions of the mediastinal testis that form partitions dividing each testis into lobules.

***STRUCTURAL FEATURES OF THE TESTES*** (Cont'd) Lobules -- partitioned areas of the testis that house the seminiferous tubules and the interstitial cells. (1) Seminiferous tubules- coiled tubules in the lobules of each testis that function in sperm production; germinal epithelium at periphery of the seminiferous tubules contains SPERMATOGENIC CELLS (immature sperm) and SUSTENCULAR CELLS (Sertoli's cells) that support and nourish the immature sperm cells. (2) Interstitial Calls- tissue in the lobule of the testis that functions in the production of male sex hormones.

UTERUS: Hollow muscular organ that receives the embryo that develops from an egg cell fertilized in the uterine tube; sustains development of fertilized egg.Serves to gestate and expel fetus. Size changes greatly during pregnancy; located medially in anterior portion of pelvic cavity; superior to vagina, usually bends forward over urinary bladder. Upper 2/3 called BODY has a dome-shaped top...FUNDUS.

***UTERINE LIGAMENTS*** (1) BROAD LIGAMENT: Anchors the ovary, uterine tubes and uterus to each other and to the pelvic wall, creating a septum across the pelvic cavity. (2) CARDINAL LIGAMENT: Fibrous sheet that extends down the lateral aspects of the uterus and vagina, anchoring them to each other (not in book). (3) ROUND LIGAMENT: extends from each side of the uterus to the body wall. (4) SACRO-UTERINE LIGAMENT: Anchors the cervical portion of the uterus to the sacral wall of the pelvic cavity (not in book).

**EVENTS IN A FEMALE REPRODUCTIVE CYCLE** (2) 5. Follicular and THECAL cells become CORPUS LUTEM cells, which secrete estrogens and progesterone. a. Estrogens continue to stimulate uterine wall development. b. Progesterone stimulates the endometrium to become more glandular and vascular. c. Estrogens and progesterone inhibit secretion of FSH and LH from the anterior pituitary gland. 6. If the secondary oocyte is not fertilized, the CORPUS LUTEM degenerates and no longer secretes estrogens and progesterone.

**EVENTS IN A FEMALE REPRODUCTIVE CYCLE** (3) 7. As the concentration of luteal hormones declines, blood vessels in the endometrium constrict. 8. The uterine lining disintegrates and sloughs off, producing a menstrual flow. 9. The anterior pituitary gland is no longer inhibited and again secretes FSH and LH. 10. The reproductive cycle repeats.

PROGESTERONE: Primary source comes from ovaries. Promotes changes in the uterus during reproductive cycle, affects mammary glands, helps regulate secretion of gonadotropins from the anterior pituitary gland.

**MAJOR EVENTS IN A FEMALE REPRODUCTIVE CYCLE** (1) 1. Anterior pituitary gland secretes FSH & LH 2. FSH stimulates maturation of a follicle. 3. Granulosa cells of the follicle produce and secrete estrogens a. Estrogens maintain secondary sex traits. b. Estrogens cause the endometrium to thicken 4. The anterior pituitary gland releases a surge of LH, which stimulates ovulation.

**MALE REPRODUCTIVE SYSTEM** 1) GUBERNACULLUM -Fibromuscular cord that guides the testes from their site or origin (kidneys of the fetus into the scrotum) into the abdominal cavity and through the inguinal canal. 2) Undescended Testes: abnormal condition termed cryptochidism.

**MALE REPRODUCTIVE SYSTEM** 1) INGUINAL CANAL -Opening in the abdominopelvic wall through which the testes pass in their descent into the scrotum. 2) SPERMATIC CORD -Suspends the testes in the scrotum; when the testes descend they each carry a Vas Deferens, blood vessels and nerves---all of which constitute the spermatic cord.

***BIRTH & FEMALE HORMONES*** (3) Prolactin: Produced by anterior pituitary; targets mammary glands; stimulates glands to produce milk. High concentrations block production and release of FSH and LH in postpartum female Oxytocin: Produced by hypothalamus; target organ is anterior pituitary. Targets mammary glands; stimulates milk let down and uterine contractions during labor.

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EPIDIDYMIS: Tightly coiled thread-like tube emerging from the superior aspect of the testis that stores sperm, secretes glycogen that helps sustain the life of the sperm cells, and during an ejaculation propels the contents into the Vas Deferens. RETE TESTIS: union of seminiferous tubules; located within the mediastinum testis

1) VAS DEFERENS- Tube with middle muscular layer that conducts sperm from the epididymis to the ejaculatory duct; 2) AMPULLA- dilated terminal portion (enlargement) of the VAS DEFERENS that conducts sperm into the ejaculatory duct. 3) EJACULATORY DUCT- conducts sperm from Vas Deferens to the urethra.

Mechanical Barriers 1. Mechanical barriers prevent sperm cells from entering the female reproductive tract. Examples of mechanical barriers are male and female condoms, diaphragms, and cervical caps. 2. Male condom is a thin membrane worn over the penis during sexual intercourse. Female condom is a small plastic bag that is inserted into the vagina prior to intercourse. 3. Diaphragm is a cup-shaped structure that covers the cervix. Cervical cap is similar to a diaphragm but adheres to the cervix by suction.

Chemical Barriers Chemical barrier contraceptives include spermicidal creams, foams, and jellies; are easy to use but have a high failure rate when used alone; more effective when used with a condom or diaphragm. Intrauterine Devices An intrauterine device is a small, solid object that is placed in the uterine cavity; IUD interferes with implantation.

**PATH OF MATURE SPERM WITHIN SCROTAL SAC** Seminiferous Tubules merge to form Rete Testis ---- Rete Testis carry sperm from the seminiferous tubules to the EFFERENT DUCTS of the testes ---- Rete Testis merge to form Efferent Ductules (Vasa Efferentia or Efferent Ducts) carry sperm from the rete testis of the testis to the EPIDIDYMIS ---- Efferent Ductules merge to form Epididymis

Coitus Interruptus Coitus interruptus is the practice of withdrawing the penis from the vagina before ejaculation; may result in pregnancy because a male may find it difficult to withdraw just prior to ejaculation. Rhythm Method The rhythm method requires abstinence from sexual intercourse two days before and one day after ovulation; results in a relatively high rate of pregnancies because accurately identifying infertile times to have intercourse is difficult.

ABP (ANDROGEN BINDING PROTEIN) - Site of production: Testes Target: Binds to testosterone Action: Initiates and promotes spermatogenesis by binding testosterone to spermatogenic cells. Higher levels of ABP enable spermatogenesis in the seminiferous tubules and sperm maturation in the epididymis.

Control of Testosterone Production and Secretion via Hypothalamus Negative Feedback: 1. Hypothalamus become INHIBITED as testosterone concentration increases. 2. Decreasing stimulation of anterior pituitary by GnRH; LH secretion falls; decreasing testosterone amount released from interstitial cells. 3. Blood testosterone concentration drops; hypothalamus becomes less inhibited and stimulates anterior pituitary to release LH. 4. Increasing secretion of LH causes interstitial cells to release more testosterone.; blood testosterone concentration increases.

SCROTUM: Pouch of skin and subcutaneous tissue that hangs from the lower abdominal region behind the penis and contains the following structural features: a) Dartos Muscle b) Medial Septum

DARTOS MUSCLE: Located in the scrotal wall; contraction brings the testes closer to the abdominal wall and causes a wrinkled appearance; regulates the internal temperature of the testis at approximately 5 degrees below normal body temperature. MEDIAL SEPTUM: Divides the scrotum into two chambers.

ORGASM: Culmination of sexual stimulation which involves physiological and psychological release, emission and ejaculation. ERECTION: Parasympathetic innervation releases nitric oxide to vasodilate central penile arteries and increase blood flow into vascular spaces of erectile tissue; this compresses peripherally located veins, reducing flow of venous blood away from the penis.

EMISSION: Movement of sperm cells and glandular secretions into the urethra under sympathetic control that stimulates peristaltic contractions of smooth muscles of all testicular ducts, the seminal vesicles, the prostate gland, and the ejaculatory ducts. EJACULATION: Expulsion of semen from the external urethral meatus of an erect penis under the control of the force of the emission and skeletal muscles at the base of the corpora cavernosa.

INTERNAL ACCESSORY ORGANS Male Reproductive System 1. Epididymis 2.Vas Deferens 3. Seminal Vesicles 4. Ejaculatory Duct 5. Prostate 6. Bulbourethral Glands (Cowpers Glands) 7. Urethra

EXTERNAL ORGANS Male Reproductive System 1. Scrotum 2. Dartos Muscle 3. Penis (Body, shaft, corpora cavernosa, corpus spongiosum) 4. External Urethral Meatus 5. Prepuce (foreskin) 6. Root

INFUNDIBULUM: Distal expanded funnel-shaped end of the uterine tube that terminates in the fimbriae that receives the oocyte and associated follicular cells at ovulation. INFUNDIBULOPELVIC LIGAMENT: Anchors each uterine tube in place by attaching the posterior surface of the infundibulum to the pelvic wall (not in book).

FIMBRIAE: Finger-like projections at the end of the uterine tube in relation to the ovary; function like tentacles creating a suction to draw the oocyte and its associated follicular cells into the tube when ovulation occurs.

***UTERINE WALLS*** (3-Layers) (1) PERIMETRIUM: Serosa; superficial layer of the uterus and part of the cervix. (2) MYOMETRIUM: Thick middle MUSCULAR layer of the uterus that functions in stretching during gestation and expelling the fetus during BIRTH; consists of longitudinal, circular and oblique layers of smooth muscle. (3) ENDOMETRIUM: Internal MUCOSAL layer with columnar epithelium of the uterus that functions in the MENSTRUAL cycle and in implantation of the zygote.

FUNDUS: Most superior portion of the uterus consists of a dome-shaped superior region of the fundus that narrows to form the CERVIX. BODY (Corpus): Superior 2/3 of the uterus into which the uterine tubes empty; consists of a dome-shaped superior region called the FUNDUS that narrows to join the CERVIX; functions as the site of implantation, growth and development of the fetus.

ICSH (Interstitial Cell Stimulating Hormone-Male) LH (Lutenizing Hormone-Female) Site of production: Anterior pituitary gland Target Organ: Interstitial cells in testes Action: Stimulates the testes to secrete testosterone and cause sperm maturation

GnRH (gonadotropin releasing hormone) - Site of production : Hypothalamus Target organ: Anterior pituitary gland Action: stimulates the anterior pituitary to secrete gonadotropins (FSH or follicle stimulating hormone and ICSH (interstitial cell stimulating hormone - same as LH in the female)

1) Orgasm in the male is accompanied by emission and ejaculation. Intense sexual stimulation---sympathetic impulses contract smooth muscle---PERISTALTIC CONTRACTION in testicular ducts epididymides, ductus Prostaglandin , and ejaculatory ducts---RHYTHMIC CONTRACTIONS in erectile columns of penis---RHYTHMIC CONTRACTIONS---in bulbourethral glands, prostate gland, and seminal vesicles--- EMISSION: semen moves into urethra ---EJACULATION: semen is forcefully expelled from urethra.

INHIBIN - Site of Production: Testes Target: Cells of the hypothalamus and the anterior pituitary gland Action: DOWN regulate spermatogenesis when sperm count is high.

Combined Hormone Contraceptives 1. Combined hormone contraceptives deliver estrogen and progestin in combination to prevent pregnancy; contains synthetic estrogen-like and progesterone-like substances. When taken daily, the drugs disrupt the normal pattern of gonadotropin secretion and prevent the LH surge that triggers ovulation. 2. Side effects of oral contraceptives includes nausea, retention of body fluids, increased pigmentation of skin, and breast tenderness.

Injectable Contraception Depo-Provera; actions of Depo-Provera are to prevent maturation and release of secondary oocytes and to alter the uterine lining. One injection of Depo-Provera lasts three months. Surgical Methods 1. Vasectomy is a surgical procedure in which a small section of each vas deferens is removed and the cut ends of the ducts are tied. 2. Tubal ligation is a surgical procedure in which uterine tubes are cut and tied so that sperm cells cannot reach an egg cell.

CORPUS LUTEM (CL): Temporary glandular structure in the ovary. Corpus Lutem cells secrete an abundant amount of progesterone and estrogens during second half of the cycle. As corpus lutem is established, the blood concentration of progesterone sharply increases. No other follicles can develop when CL. is active. At the cessation of CL, progesterone and estrogens decline. Blood vessels in endometrium constrict, reducing O2 supply and nutrients causing endometrium lining to slough off...menstrual flow.

MAMMARY GLANDS: Accessory organs of the female reproductive system specialized to secrete milk following pregnancy. Located in the subcutaneous tissue of the anterior thorax within the breasts. Composed of 15-20 irregularly shaped lobes; containing alveolar glands. Alveolar ducts drain into a lactiferous duct which leads to the nipple and opens to the outside.

The organs of the male and female reproductive systems (testes and ovaries): 1. Produce sex cells (eggs and sperm) in 2 meiotic divisions (meiosis I ans meiosis II) and hormones (continuous process) 2. Nurture sex cells 3. Transport sex cells

MEIOSIS I: Reduction Division -Daughter cells are secondary spermatocytes; haploid (23) -Parent cells are primary spermatocytes; diploid (46) -Diploid cells (46) with homologous chromosomes (each consisting of chromatids held together by a centromere) SEPARATE and their number is HALVED creating haploid cells (23).

OVARIAN ASSOCIATED LIGAMENTS 1. BROAD LIGAMENT: anchors the ovary, uterine tubes and uterus to each other and to the pelvic wall, creating a septum across the pelvic cavity. 2. SUSPENSORY LIGAMENT: anchors the superior portion of the ovary to the pelvic wall. 3. OVARIAN LIGAMENT: a rounded, cord-like thickening of the broad ligament that attaches the inferior aspect of the ovary to the uterus.

OVARIAN DESCENT: Originate from masses of retroperitoneal tissue near the developing kidneys; during development they DESCEND to locations just inferior to the pelvic brim. OVARIAN STRUCTURE: Two subdivisions (1) Medulla- lose connective tissue; containing many blood vessels, lymphatic vessels and nerve fibers. (2) Cortex - contains ovarian follicles (tiny masses of cells) that constitute the GERMINAL EPITHELIUM...dense connective tissue--Tunica Albuginea lies beneath.

***FEMALE REPRODUCTIVE SYSTEM*** 1. Primary Sex Organs (gonads): (2) Ovaries that produce eggs and female sex hormones. 2. Internal Accessory Organs: Uterine tubes (Oviducts, Fallopian tubes, Salpinx) --site of fertilization. 3. External Accessory Organs: Vulva or Pudendum; Mammary Glands

OVARIES: Primary female sex organ (gonads) that produce female sex cells (oocytes) and hormones. (2) solid ovoid structures --3.5 cm (w) x 1 cm thick. Lie in OVARIAN FOSSAE (shallow depressions) on each side in the lateral wall of the pelvic cavity. Held in position by several ASSOCIATED ligaments.

UTERINE TUBES (Fallopian Tubes, Oviducts, Salpinx): Site of fertilization; suspended by portions of broad ligament and open near the ovaries. 10 cm (L) x 0.7 cm diameter; passes medially to the uterus , penetrates its walls and opens into the uterine cavity. WALL OF UTERINE TUBE: Ciliated structure that is the site of fertilization and directs the fertilized ovum (ZYGOTE) toward the uterus.

OVULATION: Follicle matures, its primary oocyte undergoes meiosis I...resulting in a secondary oocyte and a 1st polar body. Process of OVULATION releases cells from the follicle. Release of LH from anterior pituitary gland TRIGGERS ovulation; rapidly swelling mature follicles and weakening its walls causing wall to rupture with secondary oocyte; oozing of follicular fluid

OPENINGS OF THE VESTIBULAR GLAND DUCTS: Paired openings located between the hymen and labia minora that produce a mucoid secretion that serves as a LUBRICANT during sexual intercourse.

PERINEUM: Diamond-shaped area that is surrounded anteriorly by the symphysis pubis, laterally by the ischial tuberosities and posteriorly by the coccyx; transverse line drawn between the ischial tuberosities divides the perineum into an anterior urogenital triangle that contains the external genitalia and a posterior urogenital triangle that contains the anus.

SEMINAL VESICLES : Bilateral sac-like organs located in relation to the posterior and inferior surfaces of the urinary bladder; produce a slightly ALKALINE fluid that regulates the pH of the seminal fluid; fluid contains a variety of nutrients such as FRUCTOSE that provides energy to the sperm and PROSTOGLANDINS that stimulate muscular contractions within the female reproductive organs, thereby aiding the movement of sperm toward the oocyte.

PROSTATE GLAND: Chestnut shaped structure that surrounds the proximal portion of the urethra. Gland located inferior to the bladder surrounding the urethra; secretes an alkaline fluid that regulates the pH of the seminal fluid. The functions of the secretions of the prostate gland are to neutralize sperm cell-containing fluid, to enhance motility of sperm, and to neutralize the acidic environment of the vagina.

EXTERNAL URETHRAL MEATUS - Opening at the distal end of the penis. PREPUCE (foreskin) - A loose fold of skin that originates just posterior to the GLANS PENIS and extends ANTERIORLY to cover it.

ROOT: Located within the perineum, it consists of the proximal portions of the corpora cavernosa and corpus spongiosum; two corpora cavernosa diverge LATERALLY, forming the CRURA (sing. CRUS) of the penis, which attach to the pubic arch; corpus spongiosum is enlarged between the CRURA to form the bulb of the penis.

HOMOLOGOUS CHROMOSOMES: Chromosomes that have the same sequence of genes and structure; pair during meiosis CHROMATIDS: Two complete DNA strands that are attached together. CENTROMERES: Regions that attach the chromatids of replicated chromosomes.

SPERM: Haploid male sex cells produced by meiosis. (1) Head- Contains nucleus; highly compacted chromatin ( 23 chromosomes); anterior end (acrosome) contains hyaluronidase enzyme that aids sperm cell in penetrating oocyte's ZONA PELLUCIDA. (2) Midpiece- Central, filamentous core with many mitochondria organized in a spiral.Mitochondria provide ATP for tail's lashing movement (3) Tail- Flagellum consisting of microtubules that produce a corkscrew-like movement to propel sperm

MEIOSIS II: -Parent cells are secondary spermatocytes; haploid (23) -Daughter cells are spermatids; haploid (23). -Two daughter cells go through a second division to yield four cells containing a unique set of 23 single chromosomes; mature into four sperm cells. -Haploid cells' chromatids separate, producing 4 haploid cells.

SPERMATOGENESIS: Process of sperm cell maturation. Occurs continually in males starting at puberty. Resulting sperm collects in seminiferous tubule then pass through rete testis to epididymis. During this process primary spermatocytes divide to become two secondary spermatocytes. MEIOSIS LEADS TO Genetic variability because of: 1. The random alignment of maternally and paternally derived chromosomes in meta-phase of meiosis I. 2. Crossing over - mixes up genetic traits, recombines genes.

MALE REPRODUCTIVE SYSTEM: Produce and maintain the male sex cells, to transport sex cells to the female reproductive tract, and to secrete male sex hormones. (3)Categories of Organs: 1. Primary Organ (Testes) 2. Internal Accessory Organs (Epididymis, Vas Deferens, etc.) 3. External Organs (Scrotum, Penis,etc.)

TESTES: -Produce sperm -Produces 3 important hormones (Testosterone, Androgen Binding Protein- ABP, & Inhibin) -Development originates in the abdominal cavity of the fetus retroperitoneally near the kidneys; descend into scrotal sac prior to birth under the influence of testosterone. -Primary male sex characteristic: Testosterone stimulation of testes enlargement and accessory organs.

FSH (Follicle Stimulating Hormone) - Site of production: Anterior pituitary gland Target organ: Sertoli cells of the testes. Action: Stimulates the testes to produce sperm; stimulates the sustentacular cells of the seminiferous tubules to proliferate, grow, mature, and respond to the effects of testosterone. Stimulates sustentacular cells to also produce INHIBIN (prevents over-secretion of FSH).

TESTOSTERONE - Site of Production: Testes Target organ: Body cells Actions: (1) Stimulates the formation of male reproductive organs and the descent of the testes during fetal life. (2) Stimulates the enlargement of the testes and various accessory organs of the reproductive system (3) Causes the development of male secondary sexual characteristics during puberty. (4) Stimulates SPERMATOGENESIS.

BULBOURETHRAL GLANDS: (Cowpers Glands) Pair of glands located inferior and lateral to the bladder; secrete a fluid in response to sexual stimulation that serves as a lubricant in preparation for coitus; lubricates the end of the penis in preparation for sexual intercourse.

URETHRA: Tube that carries urine from the bladder to the exterior and SPERM from the ejaculatory duct to the exterior. a) Prostatic Urethra b) Membranous Urethra c) Penile Urethra

FORNICES (fornix): Recesses in the superior portion between the internal vaginal wall and the external cervical wall that occur as the cervix extends into the superior portions of the vagina; allow the internal abdominal organs to be palpated during a physical examination and provide surgical access to the abdomen.

VAGINAL ORIFICE: Opening to the vagina which may have a hymen (thin non-functional membrane) that partially covers it. RUGAE: Longitudinal and transverse ridges of the mucosal layer that function in stretching during COITUS and gestation. BULBOSPONGIOSUS MUSCLE: An extension of the muscularis layer that is responsible for closing the vaginal orifice.

****VAGINAL WALLS**** (1) MUCOSA: Inner layer of the vaginal wall with a stratified epithelium. (2) MUSCULARIS MUCOSA: Middle muscular layer of longitudinal and circular smooth muscle; inferiorly is a band of striated muscle of the vaginal wall that helps close the vaginal orifice. (3) FIBROUS LAYER: Outermost layer of the vaginal wall that consists of dense connective tissue with elastic fibers; attaches the vagina to surrounding organs.

VULVA (Pudendum): Comprised of external accessory organs of female reproductive system (labia majora, labia minora, clitoris, and vestibular organs). These structures surround the opening of the urethra and vagina compose Vulva. MONS PUBIS: Skin covered pad of fat covered by coarse pubic hair over the symphysis pubis.